The present invention relates to an automatic machine with a high production output and great degree of operational flexibility, used for filling and closing flasks or other containers.
Flask filling and sealing machines formed by a succession of carousels are known, some of these carousels being provided with grippers for holding the flasks, while others are of the so-called star-type with perimetral alcoves into which the flasks themselves fit snugly. In the case of star-type carousels, the star devices must be replaced when there is a variation in the size of the flasks, and the flasks themselves rub against fixed parts guiding and retaining the actual flasks inside the alcoves of the star devices.
The invention aims to overcome this first drawback with a machine formed by a succession of carousels, all provided with grippers which alternately grip the flasks by the neck and by the body. In the main carousels where filling and sealing is performed, the flasks are gripped by the body so that their top part is completely free for the operating means and is in the best possible state for receiving any flow of gases which ensure hygienic or sterile conditions for packaging of the product inside the said flasks.
In machines of the known type, where cooperation between two carousels with grippers may be necessary, the grippers of a carousel are operated so as to be able to oscillate in advance or with a delay on an axis parallel to that of the carousel itself, so as to follow over a sufficiently long section the orbit on which the grippers of another carousel are moving and so as to have a sufficient amount of time for the opening and closing operations, even in the case of high peripheral speeds of the carousels. This solution involves constructional complications, in particular on account of the adjustments which are necessary when there is a variation in the size of the flasks.
According to the invention, this drawback is overcome in that the grippers are mounted on the carousels in a fixed radial arrangement and the orbits along which the grippers of consecutive carousels move intersect each other. Between the jaws of each gripper, in the middle position, there is provided a vertical opposition element which acts on the body of the flask and which is directed towards the latter with a concave self-centering profile. Moreover, the opposition elements of the grippers of a carousel, preferably the operating carousels, are immobile and the opposition elements of the grippers of the other carousels are mobile against the action of elastic means. During the transfer of a flask from one carousel to another, the flask itself is gripped, on opposite portions of its body, by the opposition elements of the grippers of the two carousels, such that the grippers themselves are able to alternate safely during opening and closing. With grippers thus designed, the flask remains permanently pressed, with its body, against the opposition element of the gripper which retains it by the neck or body, ensuring greater positional stability of the flask itself.
This solution is suitable for being able to handle a wide range of flask sizes, without having to effect major replacements of parts of the machine. Via the machine's control panel it is possible to perform automatic adjustment of the position of the opposition elements and the advance and delay in the opening sequence of the grippers and all those adjustments which are necessary when there is a variation in the size of the flasks being processed.